With the development of electronic products in the direction of miniaturization, multi-functionalization, high performance and high reliability, printed circuit boards are developed rapidly in the direction of high precision, high density, high performance, microporation, thinning tendency, and multiple stratification. The application scope has become wider and ranges from industrial large-scale computers, communication instruments, electronic measurements, national defenses, aviation, and aerospace to civilian electronics and related products. The matrix material largely determines the performance of printed circuit boards, so there is a need to develop a new generation of matrix materials. The new generation of future matrix material should have high heat resistance, low thermal expansion coefficient, and excellent chemical stability and mechanical performance.
In order to decrease the thermal expansion coefficient of the laminates, the general method is to use the resins having a low thermal expansion coefficient or to increase the content of the inorganic filler. However, the resins having a low thermal expansion coefficient have a relatively special structure and a higher cost. To increase the content of the inorganic filler may not only effectively decrease the thermal expansion coefficient of the complexes, but also greatly reduce the cost. Highly-filled resins will decrease drilling processability of the laminates. Massive fillers, such as talc, etc., are added as a lubricant to improve processability, but are ineffective. Moreover, the addition of massive fillers further deteriorates the adhesive force between the layers.
In recent years, LED (light emitting diode) has been widely applied in the fields of electric appliance indications, LED panels, LED backlight, landscape lighting, interior decoration and the like, due to the prominent features, such as low energy consumption, high efficiency and the like. High-speed development of LED also drives the developments of functional copper-clad laminate and cover film. Besides insulation, the copper-clad laminate and cover film need to have better shading function, so as to avoid penetration of light of LED light sources from the back of boards, energy waste and decrease of radiance. In order to endow the copper-clad laminate and cover film with black characteristics, materials, such as carbon black, aniline black, and the like, are commonly added into the copper-clad laminate in the industry and cover film to endow the boards with black functions.
CN102190865A discloses an epoxy resin composition for manufacturing copper-clad laminates, and mainly relates to endow copper-clad laminates with black characteristics by means of aniline black. CN101851390A discloses a black cover film, and mainly relates to endow cover film with black characteristics by means of carbon black powder. However, black pigments often bring various problems. The black pigment carbon black mainly containing carbon will prominently affect the insulating property of copper-clad laminate and cover film, and the black pigment aniline black consisting of benzene ring and nitrogen will affect the heat resistance property of copper-clad laminate, especially halogen-containing copper-clad laminate and cover film.